US school buses are going electric – here's why that's so crucial

Electric school bus adoption continues to expand in the United States.

As of last September, 1,215 electric school buses are either on order, delivered or operating. In total, there are now 13,053 committed electric school buses, almost 350 more buses since the release of WRI’s June 2022 dataset. With electric school bus commitments now spanning nearly 500 school districts in 39 states – including the recent addition of one bus in Ohio – it is evident that the tireless advocacy work at the local, state and federal levels, bolstered by continued funding opportunities across the country, is paying off.

A large portion of the buses committed overall come from a contract announced at the end of December 2021 between bus dealer Midwest Transit Equipment and SEA Electric, a manufacturer of commercial electric vehicles. This agreement promises to repower 10,000 school buses to electric over the next five years in anticipation of the demand by school transportation providers. Additional repowers are part of the 1,215 buses that are on order, delivered or operating.

More than 20 million children ride the bus to school, and 92-95% of these school buses run on diesel. Diesel exhaust, a known carcinogen, has proven links to serious physical health issues as well as cognitive development impacts. Daily exposure contributes to asthma and other respiratory diseases. Evidence increasingly suggests that children are especially susceptible to these impacts.

Students from low-income families are particularly exposed to the dangers of diesel exhaust pollution: 60% ride the bus to school, compared to 45% of students from families with higher incomes. Children of color are more likely to suffer from asthma, due in part to historically racist lending, transit, housing and zoning policies that concentrated Black and Brown communities closer to highways and other sources of vehicle-based air pollution. In addition, children with disabilities often ride longer on buses. Electrifying the entire fleet of school buses can help address these health concerns and inequalities.

Electric school buses also have no tailpipe emissions, reducing students’ exposure to harmful pollutants. In fact, reducing students’ exposure to air pollution from school buses can have positive and significant effects on student test scores — in some cases, on par with increased teacher experience levels.

Electric school buses also have significantly lower greenhouse gas emissions than diesel or propane-powered school buses, even after accounting for emissions for electricity generation. Plus, unlike other fuels, the use of electric buses will continue to reduce greenhouse gas emissions from the transportation sector as more electricity generation comes from renewable energy. School bus electrification can also offer resiliency support to the electric grid by providing access to large batteries when not in use, and add jobs in the growing electric vehicle industry.

WRI has been tracking electric school bus adoption across the United States and recently released an update covering the third quarter of 2022. Here are key findings and trends from this new data.

We consider an electric school bus “committed” when a school district or fleet operator has been awarded funding to purchase it or has made a formal agreement for a purchase with a manufacturer. Committed buses also include those that have been delivered to the school district or fleet operator, those in operation, and the 10,000 electric school bus repowers under contract by Midwest Transit Equipment and SEA Electric.

As of September 2022, in addition to these repowers, we identified 3,053 electric school buses that have been awarded, ordered, delivered, or are operating across the U.S. We also identified 28 new school districts that have committed to adding electric school buses to their fleets since June 2022, bringing the total to 483. This is an 86% increase in the number of districts from our first count in the summer of 2021, but still a small portion of the total number of districts nationwide. Just over half of these 483 districts are in California.

We have data on four phases of the electric school bus adoption process that fit under the umbrella term “committed:” “awarded,” “ordered,” “delivered” and “in operation.” As of September 2022, 846 electric school buses are delivered or in operation — about the size of the entire school bus fleet of Columbus City Schools in Ohio.

Our research shows that the average amount of time that passes between the awarding of funds to the delivery of the electric school bus is around 16 months. This range varies from less than three months to more than three years, but the amount of time has generally reduced since the first electric school bus hit the roads in 2014. Supply chain issues during the COVID-19 pandemic have exacerbated delivery delays for all school bus types and are expected to continue for some time.

We saw the first electric school bus begin operating in Ohio in September 2022, bringing the total number of states with commitments to 39. Most of these buses belong to districts or entities on the coasts and in suburban areas. California still leads in electric school bus adoption, with nearly 1,700 committed electric buses across the state, at least 37% of which are delivered or operating. This is more than four times as many buses as the next leading state. Following California, the biggest addition since June 2022 came from Maine, which gained nine electric school bus commitments.

Since the first award in 2018, 28 out of 39 states have used funds from an EPA settlement with Volkswagen — known as the Volkswagen Mitigation Trust — to purchase 646 electric school buses. However, the VW settlement still ranks second in the list of largest funding sources, after California’s Hybrid and Zero-Emission Truck and Bus Voucher Incentive Program (HVIP), which has funded 1,032 buses. Unsurprisingly, California-specific funding sources comprise five out of the 10 largest funding sources. The state’s robust incentive programs are partly why nearly three quarters of all delivered and operational electric school buses can be found there.

Most school districts with electric school buses — around three quarters — have committed to more than one bus, and 65 school districts and private fleet operators have 10 or more committed, up from just 13 in August 2021. Thirty-one percent of all entities with electric school buses have committed to five or more. These numbers suggest growing trust in electric school bus technology and market conditions, as well as wider funding availability.

The dataset includes information on “batches,” or groups of electric school buses that went through the adoption process at the same time. We consider a district’s buses to be in the same batch if one of their adoption phases — when they were awarded, ordered, delivered or first operating — occurred within roughly six months of each other. For example, if a district ordered five buses in January 2020 and then orders five more in May of 2020, those 10 buses would all be grouped into one batch. This variable can help to demonstrate adoption patterns at the school district level, like how batches differ in size and how long it takes before districts receive an additional batch.

Twenty-nine percent of districts with electric school buses have more than one batch, and nine districts — all in California — have as many as four batches. We found that most batches are small, with a median size of two buses. However, the batch sizes range widely, suggesting that they may be largely dependent on the amount and type of funding and financing available at the time.

The average time between a district’s batches is just under a year and a half. In general, districts’ later batches tended to come closer together than their first batches. Possible explanations for this trend are the increased funding opportunities in recent years or increased confidence in electric buses after the first batches.

The dataset includes 13 different electric school bus manufacturers, with three major players: Blue Bird, Thomas Built Buses and Lion Electric, in order of buses committed.

School buses are generally classified into four categories based on size and construction: the smaller types A and B, which carry between 10 and 30 passengers, and the larger types C and D, which carry between 50 and 90 students. The top three manufacturers all offer Type C electric models, which is the most common bus type, according to a 2021 maintenance survey conducted by School Bus Fleet Magazine. This aligns with our findings on electric school bus types; 52% of committed electric school buses are Type C, while 28% are the bigger Type D.

Adoption trends among school districts with different levels of air pollution and income have stayed consistent since our last update, as have the adoption patterns among communities of color. The graph above shows the distribution of electric school buses among school districts with varying percentages of “low-income” households — households earning less than twice the federal poverty level. The number of school districts with electric school buses is spread fairly evenly among low-income quartiles, but this is not the case when you look at the distribution of individual electric school buses. The largest percentage of electric school buses are in the first quartile, with the smallest share of low-income households.

Electric bus adoption appears to be occurring more equitably when looking at how the vehicles are distributed among communities of color. Eighty percent of electric school buses are located in school districts with a high population of non-white and/or Hispanic residents (defined as “Minority” in the Environmental Protection Agency’s EJScreen data). Stakeholders – including policymakers, utilities, nonprofit organizations and teams charged with program design and implementation – should commit to ensuring this trend continues to help address the inequities of on-road air pollution.

We compiled data on concentrations of Particle Matter (PM2.5) and ozone in school districts because of the harmful health effects, close linkage to diesel exhaust, and the availability of data. As seen in the above chart, school districts with the highest levels of PM2.5 air pollution have committed more electric school buses. The trend differs slightly with ozone pollution. While the highest quartile of ozone pollution also contains the most buses, 23% of buses are in areas with the lowest levels of ozone, compared to 4% of buses that are in areas with the lowest levels of PM2.5.

Overall, committed electric school buses are largely concentrated in historically underserved school districts, but more efforts could be focused on ensuring electric school buses are accessible to more low-income communities. Since an electric bus and associated charging infrastructure currently cost more than a diesel bus upfront, funding support is crucial for low-income districts to transition to electric.

However, the metrics we have chosen are by no means comprehensive. WRI will be conducting more in-depth research on the equity of electric school bus adoption and continuing to work alongside partners to ensure that underserved communities remain front-and-center in the transition.

Our most recent update to WRI’s Electric School Bus Adoption dataset saw a steady increase in the number of committed buses. This update includes data through the end of September 2022, but in October 2022, the EPA announced its first funding awards through the Clean School Bus Program, adding substantially to the number of committed electric school buses. These awards will be reflected in our next update, scheduled for the spring of 2023.

The Clean School Bus Program granted over $900 million exclusively for electric school buses, prioritizing high-need or low-income, rural, and tribal schools. Given the tremendous volume of applications that EPA received, four times the originally planned amount, EPA roughly doubled the initial rebate funding provided in total to meet some of the demand. Over 2,400 electric school buses were awarded to districts in all 50 states, the District of Columbia, American Samoa, Guam, Puerto Rico and the U.S. Virgin Islands. Additionally, the historic passage of the Inflation Reduction Act of 2022 (IRA) supports the electric school bus transition by creating tax credits for the purchase of an electric school bus and the installation of electric vehicle charging stations in low-income communities. Also, the IRA provided EPA with an additional $1 billion in funding to assist the transition of Class 6 and Class 7 vehicles to electric, for which electric school buses will likely be eligible.

It is clear that electric school buses now have nationwide momentum, especially as new manufacturing plants start production in Illinois and West Virginia, as several states pass legislation committing to equitable adoption of electric school buses, and as interest in electric repowers of fossil-fuel buses increases.

If progress toward an all-electric school bus fleet is to continue, policymakers at the federal and state levels, including state utility regulators, need to increase funding opportunities and ensure they are accessible to communities that would benefit most from school bus electrification.